This proposed research involves three breeds of dogs with spontaneous familial ocular diseases which are potential animal models for human diseases. The disorders are corneal dystrophy and posterior subcapsular cataracts in the Siberian Husky, retinal dysplasia with total detachment in the Labrador Retriever and multifocal retinal dysplasia in the American Cocker Spaniel. Breeding colonies of affected dogs have been assembled and progeny are available for studies. Preliminary clinical studies, pedigree analysis and histopathology have established the findings and confirmed the potential of these animal models.